1. Field of the Invention
The present invention relates to a prepolymerized catalyst obtained by prepolymerization of olefin and a method for olefin polymerization using the same. More specifically, the present invention relates to a prepolymerized olefin polymerization catalyst prepared in such a way that high molecular weight macromonomers are encapsulated around the catalyst and to a method of olefin polymerization using the prepolymerized catalyst which produces polyolefin with a high melt strength.
2. Description of the Related Art
Compared to polyethylene, conventional linear polypropylenes are not suitable for melt processing (e.g., foaming, heat molding, extrusion coating, etc.) due to a low melt strength. However, a high melt strength can be achieved by introducing long chain branching into the polypropylene. Long chain branching reduces attractive forces between macromolecular chains during processing and acts to increase melt strength by crosslinking with neighboring chains during molding processes. Production of high melt strength polyolefins with long chain branching typically includes the step of forming polyolefin radicals exiting a polymerization reaction vessel by electronic radiation or by a reaction extrusion method followed by reacting these radicals to introduce long chain branching into the linear structure. If a polymerization method could be developed that was capable of directly polymerizing olefins to form a high melt strength polyolefin useful as a molding material, it is expected that the use of polyolefins as molding materials could be expanded.